Adelphius or Adelfius may refer to:
(4th century), Egyptian bishop Clodius Celsinus Adelphius (fl. 333–351), Roman politician Adelfius, a bishop from Britain noted as attending the 314 Council of Arles Adelfius I (bishop of Limoges) (. ), grandfather of St Ruricius Adelphius of Poitiers (), bishop Adelfius II (bishop of Limoges) () Adelfius III (bishop of Limoges) ()
See also Adelphus, bishop of Metz Adelfer Adelfia Adelfo Adelpha Adelphi (disambiguation) Adelphia (disambiguation)